3com 5500 用户手册

C

HAPTER

 4: V

OICE

 VLAN C

ONFIGURATION

 G

UIDE

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You cannot add a port operating in automatic mode to the voice VLAN 
manually. Therefore, if you configure a VLAN as a voice VLAN and a protocol 
VLAN at the same time, you will be unable to associate the protocol VLAN with 
such a port. Refer to “Configuring Protocol-Based VLAN” on page 23 for 
description on protocol VLAN.

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You cannot set the voice VLAN as the default VLAN on a port in automatic 
mode.

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The switch supports only one voice VLAN.

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You cannot enable voice VLAN on a port configured with the Link Aggregation 
Control Protocol (LACP).

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Only a static VLAN can be configured as a voice VLAN.

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When the number of ACL rules applied to a port reaches the upper threshold, 
enabling voice VLAN on the port fails. You can use the display voice vlan 
error-info command to locate such ports.

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In the voice VLAN operating in security mode, the device allows only the 
packets whose source address matches a recognizable voice device vendor OUI 
to pass through. All other packets, including authentication packets such as 
802.1x authentication packets, will be dropped. Therefore, you are 
recommended not to transmit both voice data and service data in the voice 
VLAN. If that is needed, disable the security mode of the voice VLAN.